diff options
| author |   Ben Zhang <benzh@chromium.org> | 2015-05-21 09:50:34 -0700 |
|---|---|---|
| committer |   Tony Luck <tony.luck@intel.com> | 2015-05-21 09:50:34 -0700 |
| commit | e036bd330d21e929e94ed4d5432f9d279b19ce47 (patch) | |
| tree | 6b8dfaecbbe53c2b8172e32283e40e128c746e6b /fs/pstore | |
| parent | fs/pstore: Optimization function ramoops_init_przs (diff) | |
| download | linux-dev-e036bd330d21e929e94ed4d5432f9d279b19ce47.tar.xz linux-dev-e036bd330d21e929e94ed4d5432f9d279b19ce47.zip | |
pstore/ram: verify ramoops header before saving record
On some devices the persistent memory contains junk after a cold boot,
and /dev/pstore/dmesg-ramoops-* are created with random data which is
not the result of a kernel crash.
This patch adds a ramoops header check and skips any
persistent_ram_zone that does not have a valid header.
Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/ram.c | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index f29373d299b0..d84ce222c516 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -186,12 +186,34 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, ssize_t size; ssize_t ecc_notice_size; struct ramoops_context *cxt = psi->data; - struct persistent_ram_zone *prz; - int header_length; + struct persistent_ram_zone *prz = NULL; + int header_length = 0; + + /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but + * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have + * valid time stamps, so it is initialized to zero. + */ + time->tv_sec = 0; + time->tv_nsec = 0; + *compressed = false; + + /* Find the next valid persistent_ram_zone for DMESG */ + while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) { + prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, + cxt->max_dump_cnt, id, type, + PSTORE_TYPE_DMESG, 1); + if (!prz_ok(prz)) + continue; + header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), + time, compressed); + /* Clear and skip this DMESG record if it has no valid header */ + if (!header_length) { + persistent_ram_free_old(prz); + persistent_ram_zap(prz); + prz = NULL; + } + } - prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, - cxt->max_dump_cnt, id, type, - PSTORE_TYPE_DMESG, 1); if (!prz_ok(prz)) prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt, 1, id, type, PSTORE_TYPE_CONSOLE, 0); @@ -204,13 +226,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, if (!prz_ok(prz)) return 0; - if (!persistent_ram_old(prz)) - return 0; - - size = persistent_ram_old_size(prz); - header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time, - compressed); - size -= header_length; + size = persistent_ram_old_size(prz) - header_length; /* ECC correction notice */ ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); |